2 Answers
2

To summarize the set of keyboard shortcuts with the addition of @soulshined's input:

If I have two windows from different apps I can switch with ⌘ Command-Tab.

If I have two windows from the same app I can switch with ⌘ Command-`.

If I have two full-screen windows from the same app then ⌘ Command-` doesn’t work, but I can switch with ⌃ Ctrl-← or → (or ⌃ Ctrl-← or →; I chose ⌃ Ctrl-← or → to
avoid conflict with browser back/forward shortcuts).

If I have two full-screen windows from the same app on different
monitors then ⌃ Ctrl-← or → doesn’t work but ⌘ Command-` does.

If I have two full-screen windows from the same app on different
monitors and the target window is currently not in front then ⌘ Command-` and ⌃ Ctrl-← or → both fail to work. I have to ⌘ Command-Tab to another app that is on the target monitor, then ⌃ Ctrl-← or → to the target window. Correction: ⌃ Ctrl-← or → scrolls through spaces on the original monitor, not the target monitor, so there's actually no way to do this that I know of.

Aside: if I enable the keyboard shortcuts for “Switch to Desktop 1” and “Switch to Desktop 2” and use two monitors, the shortcuts won’t work if the specified desktop is not assigned to the current monitor.

Oh my god, this is stupid. I work in full screen mode 90% of the time and very often have the need to switch between different instances of the same app. It makes no sense to disable the Cmd-` shortcut, just because a window is in full screen mode, does it?
– anothernodeOct 16 '17 at 12:06

I have outlined below what you should do. In short, yes it is possible, because I use it everyday

Go to System Preferences → Keyboard → 'Shortcuts' tab.

Click on the 'Mission Control' option in the left sidebar.

Now on the right sidebar you will see a Mission Control heading with a disclosure triangle next to it. Click on the triangle to show additional options.

You will see predefined options for you to select from; however, the keyboard shortcuts can be edited as necessary. I have mine set to Command-→ to switch between spaces.

Visual aid:

If this doesn't work for you, it's because you don't have your displays segregated. If you're running more than one monitor:

Go to System Settings > Mission Control and check 'Displays have separate Spaces'.

You will have to log out and log back in for it to take effect.

Additionally, for further desktop organization you can set your apps to only appear on a certain window or space, so that way that application only populates in the space you designate. You can do this by going to System Preferences → Mission Control and check "Group windows by application" so there isn't cluttering of applications.

NOTE

This is not OS specific (works with Mavericks or Yosemite) and is not prejudiced to full screen apps. In other words, since you're switching spaces it doesn't matter what's in the space or how it's displayed; it will switch regardless. Lastly, it functions regardless of your screen output, setup, or format. I have three monitors and it only affects the active display.

@AshleyG 👍 Thanks. It doesn't emulate the command but if both windows of the same application are full screen and in different spaces it essentially emulates the effect.
– soulshinedDec 31 '14 at 17:38

Exploring this a bit more I've found a situation where I can't get a window visible using keyboard shortcuts. I've summarized everything in a new answer as comments don't allow the length and formatting required.
– Ashley GDec 31 '14 at 18:55